Fix broken links in OFL font descriptions (update moved, remove dead)

[emmamarichal]

What this PR does

This PR cleans up external links across ofl/**/DESCRIPTION*.html. Every link in
these files was tested, and broken ones were handled in one of three ways:

1. Updated links that only moved (the content still exists, just at a new URL):

• Legacy google.com/fonts/specimen/<Family> and google.com/webfonts/specimen/<Family>
  URLs → updated to https://fonts.google.com/specimen/<Family>.
• Plain http:// links whose https:// version is live → upgraded to HTTPS.
• A few sites that rebranded/moved → pointed to their current address.

2. Removed links that are truly dead (no valid destination):

• Domains that no longer resolve, parked / "for sale" pages, hard 404/410s, and
  links to shut-down services (Google Code, Google+).
• Removal keeps the text intact: a link alone in its paragraph removes the empty
  paragraph; an inline link is unwrapped, keeping the surrounding wording. Dead links
  were not replaced with substitutes (no archive snapshots, no guesses).

3. Reviewed the ambiguous ones by hand, case by case — e.g. when only a sub-page
404s but the site is fine, I pointed the link to the site instead of deleting it.

Reference links that are intentionally kept even if currently empty (e.g. Wiktionary
script-category pages, which may be populated later) were left untouched on purpose.

The commits are split for easy review: removals, automated URL updates, and the
manual fixes are in separate commits.

Verification

After applying the changes, I re-ran a full automated audit that re-checks every
link in the current state of the files, and I reviewed the results by hand. Anti-bot
responses (HTTP 403/429 on live sites) were left untouched.

A per-change summary (grouped by type, marked automated vs. manual) is attached to
help review. pr_summary.html

Scope

This PR covers ofl/ only. A follow-up PR will do the same for catalog/designers/.

Tooling note

Link detection, migration and removal were assisted by Claude (Anthropic), model
Claude Opus 4.8. All changes were verified by hand before committing.